We have 3 new (4/1/13) Ferris 3100Z, 61" 38hp. Belts have been replaced 2 & 3 times each: #1-39,139 hrs; #2-24,68,120 hrs; #3-10,24,138 hrs. First to fail was factory. I found a v-belt supplier on the internet whose belts last 4x longer and cost about $15 each. My local dealer is new to Ferris and top notch. but the factory is very slow to ship parts. I will ask about the keep kit.